EMG Data Research Articles

The Impact of a Rotating Balance Platform on Leg Neuromuscular Activity in Healthy Young Adults

Balance is a functional activity that must be implemented in every type of rehabilitation for the back and lower extremities’ injury and pathology. With issues in these regions, balance is lessened, requiring exercises that enhance the patient’s stability. Purpose: To determine the impact of activities on a rotating balance platform with tracking tasks for lower limb muscle activation. Method: Twenty-five participants performed seven tasks on a balance board with a fixed middle fulcrum. For each trial, activation of the gastrocnemius and tibialis anterior muscles was recorded using surface electromyography. Upon examination of the EMG data, the following variables were quantified: time to peak muscle activation, time to decay of muscle contraction, and time of muscle contraction duration. Results: A repeated measures ANOVA revealed that TA exhibited significant modifications (P<0.001) with less time to peak, duration, and decay, whereas GA only notably compensated (P<0.001) with shorter duration and decay. Conclusion: For subjects with balance alterations due to slower nerve conduction or muscle weakness in the lower limb, we suggest incorporating activities with rotational movements on the balance board, where muscle activation is challenged due to surface and tracking activities. When endurance is prescribed, front-to-back tasks contribute to prolonged muscle activation. Balance rehabilitation should consider muscle activation timing with tracking tasks for more precise and targeted muscle execution.

An Objective, Information-Based Approach for Selecting the Number of Muscle Synergies to be Extracted via Non-Negative Matrix Factorization.

Muscle synergy analysis is a useful tool for the evaluation of the motor control strategies and for the quantification of motor performance. Among the parameters that can be extracted, most of the information is included in the rank of the modular control model (i.e. the number of muscle synergies that can be used to describe the overall muscle coordination). Even though different criteria have been proposed in literature, an objective criterion for the model order selection is needed to improve reliability and repeatability of MSA results. In this paper, we propose an Akaike Information Criterion (AIC)-based method for model order selection when extracting muscle synergies via the original Gaussian Non-Negative Matrix Factorization algorithm. The traditional AIC definition has been modified based on a correction of the likelihood term, which includes signal dependent noise on the neural commands, and a Discrete Wavelet decomposition method for the proper estimation of the number of degrees of freedom of the model, reduced on a synergy-by-synergy and event-by-event basis. We tested the performance of our method in comparison with the most widespread ones, proving that our criterion is able to yield good and stable performance in selecting the correct model order in simulated EMG data. We further evaluated the performance of our AIC-based technique on two distinct experimental datasets confirming the results obtained with the synthetic signals, with performances that are stable and independent from the nature of the analysed task, from the signal quality and from the subjective EMG pre-processing steps.

Determining C5, C6 and C7 myotomes through comparative analyses of clinical, MRI and EMG findings in cervical radiculopathy

ObjectiveThere are many myotome charts in the literature, but few studies have presented actual data to support their identification. We aimed to determine C5/C6/C7 myotomes based on clinical and EMG data of patients with cervical spondylotic radiculopathy (CSR) having a single-root lesion confirmed by MRI. MethodsMedical Research Council (MRC) scores and EMG findings were retrospectively reviewed for patients enrolled from our EMG database. ResultsEnrolled were 25 patients (10 C5, 6 C6, and 9 C7 CSR). In C5 CSR, weakness or denervation potentials in EMG, or both, were observed in the deltoid (Del) and infraspinatus (Isp) muscles for all patients, and in the biceps brachii (BB) and brachioradialis (BR) muscles for 9/10 and 8/9 patients, respectively. In C6 CSR, weakness of the wrist extensor and/or denervation of the extensor carpi radialis longus (ECRL)/extensor carpi radialis brevis (ECRB), and those of the pronator teres (PT) were observed for all patients. Weakness was not observed for any other muscle in C6 CSR. Denervation potentials of ECRL were found in 5/8 and 3/5 patients with C5 and C6 CSR, respectively, whereas those of ECRB were found in 1/5, 6/6, and 2/5 patients with C5, C6 and C7 CSR, respectively. In C7 CSR, weakness/denervation of the triceps brachii (TB) and denervation potentials of the flexor carpi radialis (FCR) were observed for all patients. Denervation potentials in PT and weakness/denervation of the extensor digitorum (ED) were observed in 2/9 and 4/9 patients, respectively. ConclusionSuggested dominant myotomes are: C5 for the Del, Isp, BB, and BR, C5/6 for the ECRL, C6 > C7 for the ECRB and PT, and C7 for the TB and FCR. SignificanceThe current study identified dominant myotomes that differ from the existing literature.

Effects of break scheduling strategies on subjective and objective measures of neck and shoulder muscle fatigue in asymptomatic adults performing a standing task requiring static neck flexion

Sustained non-neutral postures of the head/neck are related to transient neck discomfort and longer-term disorders of the neck. Periodic breaks can help but the ideal length and frequency of breaks are yet to be determined. The current study aimed to quantify the effects of three work-rest strategies on fatigue development. Participants maintained a 45-degree neck flexion posture for a total of 60 min and were provided 3 min of rest distributed in different ways throughout the experiment [LONG (one, 3-min break), MEDIUM (two, 1.5-min breaks), or SHORT (five, 36-s breaks)]. Surface electromyography data were collected from the bilateral neck extensors and trapezius. Subjective discomfort/fatigue ratings were also gathered. Results of the analysis of the EMG data revealed that the SHORT condition did not show increased EMG activity, while LONG [21%] and MEDIUM [10%] did (p < 0.05), providing objective data supporting the guidance of short, frequent breaks to alleviate fatigue.

ELECTROMYOGRAPHIC ANALYSIS OF GLUTEAL RECRUITMENT: AN EXPLORATION OF ACTIVATION DURING JUMPING TASKS.

Inability to maintain proper alignment of the pelvis and femur due to gluteal muscle weakness has been associated with numerous lower extremity pathologies. Therefore, many lower extremity rehabilitation and injury prevention programs employ exercises that target gluteal muscle strength and activation. While information regarding muscle activation during exercises that are typically done in the beginning stages of rehabilitation is available, evidence regarding the gluteal muscle activity during more functional and advanced exercises used during later stages of rehabilitation is sparse. To explore the recruitment of the gluteal muscles during jumping tasks in healthy participants to determine which jumping exercise best elicits gluteal muscle activation. Prospective cohort design. Eighteen healthy recreational athletes (23.5 ± 3.8 years, 8M/10F, 67.56 ± 3.2 inches, 66.73 ± 9.5 kg) completed three trials of four jumping tasks: hurdle jump, split jump, V2 lateral jump, and cross-over jump in random order. Surface EMG electrodes were placed on each participant's bilateral gluteus medius (GMed) and maximus (GMax) to measure muscle activity during the jumping tasks. Maximal voluntary isometric muscle contraction (MVIC) was established for each muscle group in order to express each jumping task as a percentage of MVIC and allow standardized comparison across participants. EMG data were analyzed for all jumps using a root-mean-square algorithm and smoothed with a 62.5 millisecond time reference. Rank ordering of muscle activation during jumping tasks was performed utilizing the peak percent MVIC recorded during each jumping task. Three of the jumping tasks produced greater than 70% MVIC of the GMed muscle. In rank order from highest EMG value to lowest, these jumping tasks were: crossover jump (103% MVIC), hurdle jump (93.2% MVIC), and V2 lateral jump (84.7% MVIC). Two of the exercises recruited GMax with values greater than 70% MVIC. In rank order from highest EMG value to lowest, these jumping tasks were: hurdle jump (76.8% MVIC) and split jump (73.1% MVIC). Only the hurdle jump produced greater than 70% MVIC for both GMed and GMax muscles. The jumping task that resulted in greatest activation of the GMed was the crossover jump, while hurdle jump led to the greatest activation of the GMax. The high %MVIC for the GMed during the crossover jump may be attributed to lack of maximal effort or lack of motivation during performance of maximal contractions during the manual muscle testing. Alternatively, substantial co-contraction of core muscles during the crossover jumping task may have led to higher values. 2b Individual Cohort Study.

REAL-TIME HAND GESTURE CLASSIFICATION USING CRNN WITH SCALE AVERAGE WAVELET TRANSFORM

It is very useful in the human computer interface to quickly and accurately recognize human hand movements in real time. In this paper, we aimed to robustly recognize hand gestures in real time using Convolutional Recurrent Neural Network (CRNN) with pre-processing and overlapping window. The CRNN is a deep learning model that combines Long Short-Term Memory (LSTM) for time-series information classification and Convolutional Neural Network (CNN) for feature extraction. The sensor for hand gesture detection uses Myo-armband, and six hand gestures are recognized and classified, including two grips, three hand signs, and one rest. As the essential pre-processing due to the characteristics of EMG data, the existing Short Time Fourier Transform (STFT), Continuous-time Wavelet Transform (CWT), and newly proposed Scale Average Wavelet Transform (SAWT) are used, and thus, the SAWT showed relatively high accuracy in the stationary environmental test. The CRNN with overlapping window has been proposed that can improve the degradation of real-time prediction accuracy, which is caused by inconsistent start time and hand motion speed when acquiring the EMG signal. In the stationary environmental test, the CRNN model with SAWT and overlapping window showed the highest accuracy of 92.5%. In the real-time environmental test, for all subjects learning, 80% accuracy and 0.99 s time delay were obtained on average, and for individual learning, 91.5% accuracy and 0.32 s time delay were obtained on average. As a result, in both stationary and real-time tests, the CRNN with SAWT and overlapping window showed better performance than the other methods.

Influence of Kinesio tape on lower limb muscular activity after knee joint rehabilitation program

This study aimed to identify the effect of using Kinesio tape on the neuromuscular activity of quadriceps muscle after the rehabilitation program of the knee joint. Ten players participated in present study (age: 26.20 ± 1.69 years; body mass: 77.10 ± 4.48 kg; height: 172.30 ± 5.46 cm). The EMG signals were stored at a sampling frequency of 1000 Hz and digitized using a 16-bit analogue to digital (A/D) converter. EMG data were processed using ProEMG software (Myon 320, Schwarzenberg, Switzerland). Raw EMG data was band-pass (20 Hz- 450 Hz) applying a Butterworth filter. The signals were preprocessed using full-wave rectified and a linear envelope obtained using the Root Mean Square (RMS) approach with a window size of 300 ms. Data was normalised to the peak muscle activity value over each attempt (%MAX). Descriptive statistics were reported as means and standard deviations (mean ± Std. Deviation). The normality of the data was analyzed using the Shapiro-Wilk test. Independent T-test was used to detect significant differences and compare the mean of each variable between single-leg squat and balance tests. The statistical analysis was performed using IBM SPSS software Statistics v21 SPSS Inc., USA) with significance level defined as p < 0.05 for each test. The results of the present study showed that applying KT around the knee joint after rehabilitation program does not promote immediate changes or effects on the lower limb muscle activities of (VL, RF, VM, BF, ST, L_GAST, and M_GAST

Crumley's Classification of Laryngeal Synkinesis: A Comparison of Laryngoscopy and Electromyography.

Applying the principles of misdirected nerve regeneration to the larynx, Roger Crumley in 1989 coined the term laryngeal synkinesis (LS) which he later (2000) classified into 4 types (type I - good voice, type II - involuntary twitches and poor voice, type III - adduction during inspiration, type IV - abduction during phonation). Neurophysiological data were not available for all LS patients at that time. The current study was undertaken to utilize and test the Crumley classification for a clinical interrater comparison and, secondly, compare predicted with actual laryngeal electromyography (LEMG) results. Descriptive study. Laryngoscopic and LEMG data of patients with unilateral vocal fold paralysis (VFP) of 6 months duration or longer were combined for retrospective evaluation. Forty-five data sets were available for laryngoscopic classification by two local laryngologists and by Roger Crumley. Twenty-three data sets with complete thyroarytenoid (TA) and posterior cricoarytenoid (PCA) - EMG data were used to compare predicted with actual LEMG results. Local laryngologists were able to classify 24 of 45, Crumley 30 of 45 cases into one of the 4 synkinesis types. There was substantial agreement between examiners (Cohens Kappa 0.66 [P < .001]). Comparison of predicted and actual LEMG data showed only moderate agreement. EMG sykinesis rates were lower in TA than in PCA and highest in Crumley type I cases. The Crumley classification is helpful in describing and understanding synkinesis. It does not always correlate predictably with actual LEMG data. A complete LEMG mapping of all intrinsic muscles may improve understanding of chronic VFP. 4. Laryngoscope, 131:E1605-E1610, 2021.

Effect of Stretching Protocols on Glenohumeral-Joint Muscle Activation in Elite Table Tennis Players.

Several studies report static-stretch-induced deficits and dynamic-stretch performance improvement after intervention. To investigate the muscle activation of the forehand and backhand in table tennis players after experiencing static- and dynamic-stretching protocols. A total of 24 elite male table tennis players (age 22.7 [3.46]y, height 1.78 [0.03]m) were tested before and 0, 10, 20, and 30min after the 3 conditions (dynamic stretch, static stretch, and no stretch). The MEGA ME6000 (Mega Electronics, Kuopio, Finland) was used to capture the surface EMG data of the anterior deltoid, middle deltoid, posterior deltoid, biceps, and triceps muscles. Muscle activation data of the pretest were compared with posttest 0, 10, 20, and 30min. These data were also compared between 3 different conditions (dynamic stretch, static stretch, and no stretch). A 2-way repeated-measures analysis of variance indicated significant differences in the forehand and backhand, and Bonferroni test as a post hoc comparison revealed significant differences between the pretest and posttests in several muscles (P < .05). Furthermore, there were significant differences in the posttest between the 3 conditions (P < .05). In general, there was a short-term effect of static- and dynamic-stretching protocols on glenohumeral-joint muscle activation in elite table tennis players. The static and dynamic stretching presented a decrease and increase, respectively, in muscle activation up to 30min after stretching. In conclusion, the additive and subtractive effects of dynamic- and static-stretching protocols on muscle activation seem to persist after 30min.

Clinical analysis of selective laryngeal reinnervation using upper root of phrenic nerve and hypoglossal nerve branch in the treatment of bilateral vocal fold paralysis

Objective: To evaluate the airway and voice quality improvement in patients with bilateral vocal fold paralysis (BVFP) who underwent selective laryngeal reinnervation surgery. Methods: From January 2012 to December 2016, a retrospective study was conducted in 39 patients with BVFP who underwent selective laryngeal reinnervation surgery in Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Navy Medical University. All patients were examined by videostroboscopy, vocal function assessment, laryngeal electromyography and pulmonary function test before and after the surgery, and followed up for at least 2 years to evaluate the efficacy and safety of the surgery.Wilcoxon signed rank test was used to analyze the G score and VHI-10 score data. Paired t-test was used to analyze acoustic parameters, MPT values and pulmonary function parameters. Results: Postoperative infection and hemorrhage occurred in one patient separately.Videostroboscopic videos showed that at 4-8 months postoperatively, vocal folds in 35 patients achieved moderate or severe abduction during inspiration, 2 patients only achieved mild abduction, 2 patients showed no abduction,while all patients achieved adduction in bilateral vocal cords during phonation. The recovery rate of moderate-to-severe abduction was 89.7% (35/39), and these patients were decannulated successfully. At 12 months after operation, G score and VHI-10 score were significantly lower than those before operation (P<0.05), and the acoustic parameters jitter, shimmer, HNR and MPT were significantly improved (P<0.05). Most of the parameters of the pulmonary function test at 3 months postoperatively returned to the normal reference level, while the maximum inspiratory pressure (PImax) at 12 months after operation was still slightly lower than the normal level, but it was significantly improved compared with preoperative value (P<0.05). The EMG data at 12 months postoperatively showed full interference potentials in 37 patients in bilateral posterior cricoarytenoid muscles during inspiration, and full interference potentials in bilateralthyroarytenoid muscles during phonation. Obvious misdirected regeneration electric activitieswere found in two of them. Potentials in posterior cricoarytenoid muscle were weak in 2 cases with poor abduction. During long-term follow-up, only one case showed decreased abduction, but did not affect respiratory function. Conclusions: The selective laryngeal reinnervation procedure applied in the present study can restore physiological motion of vocal cords. The success rate was high, the curative effect was stable, and the complications were rare. It is worth of promotion.

Effect of Kinesio Tape for Fascia on Trunk Muscle Activity during Plank

Purpose: Many studies have reported increased muscle activities in treatments using kinesio tape. However, most studies have focused on only muscles, so the effects of kinesio tape on structures other than the muscles are unknown. The purpose of this study is to explore the effect of kinesio tape for the fascia on trunk muscle activity during plank. Methods: Eighteen healthy participants took part in this study. The participants were asked to perform the plank in two conditions: on stable surface and unstable surface. Two kinesio tapes were attached along the spiral line introduced in the anatomy train. EMG was measured in each condition. EMG data were collected before and after attaching kinesio tape in each condition. Repeated analysis of variance (repeated ANOVA) was conducted to compare EMG activities levels between conditions. Results: EMG activities levels of trunk muscles, especially rectus abdominis and erector spinae activities were significantly increased dur ing the plank with KT on both stable and unstable surfaces. Conclusion: KT applying on the fascia of targeted muscle increases the muscle activity. Therefore, we can also focus on the fascia to in crease muscle activities not only on muscles.

Shoulder muscle force and electromyography activity during make versus break tests

BackgroundShoulder muscle force is commonly assessed during clinical examination using both an isometric “make” test against a fixed resistance or a “break” test where the examiner exerts enough force to break the isometric contraction. The purpose of this study was to explain the difference in force produced during these two forms of testing. MethodsData were collected on 25 subjects. Both shoulder external rotation and elevation force were measured over three trials, isometrically, for approximately 3 s, after which the examiner exerted enough force to move the arm. Surface EMG was recorded for the infraspinatus for external rotation and middle deltoid for elevation. Peak isometric and break forces, and normalized, averaged EMG data at peak isometric and break forces were compared with paired t-tests. FindingsExternal rotation peak break force was 46.9% (SD33.6, range − 3% to 108.6%) greater than isometric force (p < 0.01). EMG for the infraspinatus was 17.0% (20.8) greater at break (p < 0.01). For elevation, peak break force was 63% (73.1, range − 3.5 to 238.16%) greater than isometric force (p < 0.01). EMG for the middle deltoid was 11.1% (30.8) greater during peak break force (not significant). InterpretationsThere is a difference in both force and muscle activity between “make” and “break” tests. Clinicians should use a consistent method when measuring force and a break test will provide the maximum force. The cause of greater force produced during a break test is likely attributable to the brief eccentric contraction rather than greater recruitment. Future analysis will include examining the differences in make and break forces based on activity levels.

Running mechanics and leg muscle activity patterns during early and late acceleration phases of repeated treadmill sprints in male recreational athletes.

We determined whether running mechanics and leg muscle activity patterns for pre-activation (50ms prior to foot contact) and loading (first half, second half and entire stance) phases vary between early, late and entire acceleration phases during repeated treadmill sprints. Ten male athletes performed three sets of five 5-s sprint accelerations (25-s and 3-min recovery between sprints and sets, respectively) on an instrumented treadmill. Ground reaction forces and surface EMG data (root mean square values of vastus lateralis, rectus femoris, biceps femoris, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles of the right leg) corresponding to early, late and entire acceleration (steps 2, 4 and 6; steps 8, 10 and 12; and all steps, respectively) have been compared. Independently of fatigue, vertical and horizontal forces, contact time, step length, and step frequency differed as running velocity increased over different sprint acceleration sections (all P < 0.05). For pre-activation, first half, second half and entire stance phases taken separately, each of the six studied muscles displayed specific main sprint number and analysis section effects (all P < 0.05). However, there was in general no significant interaction between sprint number and analysis section (all P > 0.27). During repeated treadmill sprints, ground reaction force variables and leg muscle activity patterns can vary between early, late and entire acceleration phases. Identification of neuro-mechanical adjustments across the gait cycle with fatigue, however, did not differ when considering all steps or only a few steps during the early or late acceleration phases.

Between-day repeatability of lower limb EMG measurement during running and walking

There are minimal data describing the between-day repeatability of EMG measurements during running. Furthermore, there are no data characterising the repeatability of surface EMG measurement from the adductor muscles, during running or walking. The purpose of this study was to report on the consistency of EMG measurement for both running and walking across a comprehensive set of lower limb muscles, including adductor magnus, longus and gracilis. Data were collected from 12 lower limb muscles during overground running and walking on two separate days. The coefficient of multiple correlation (CMC) was used to quantify waveform similarity across the two sessions for signals normalised to either maximal voluntary isometric contraction (MVIC) or mean/peak signal magnitude. For running, the data showed good or excellent repeatability (CMC = 0.87–0.96) for all muscles apart from gracilis and biceps femoris using the MVIC method. Similar levels of repeatability were observed for walking. Importantly, using the peak/mean method as an alternative to the MVIC method, resulted in only marginal improvements in repeatability. The proposed protocol facilitated the collection of repeatable EMG data during running and walking and therefore could be used in future studies investigating muscle patterns during gait.

Time-frequency analysis of muscle activation patterns in people with chronic ankle instability during Landing and cutting tasks

BackgroundPeople with chronic ankle instability (CAI) exhibit neuromuscular deficits. Previous studies, however, only investigated magnitudes of muscle activation and not the time-frequency domain. Research questionDo people with CAI exhibit differences in muscle activation patterns in the time-frequency domain during landing, anticipated cutting, and unanticipated cutting compared to matched controls? MethodsEleven people with CAI and eleven healthy matched controls (CON) performed landing, anticipated cutting, and unanticipated cutting as surface EMG of the lateral gastrocnemius, medial gastrocnemius, fibularis longus, soleus, and tibialis anterior were recorded. The time-frequency domain of surface EMG data was analyzed with wavelet transformations and principal component analysis (PCA), PC scores were compared across group, task, and muscle with three-way ANOVAs. ResultsThe PCA extracted two PCs that captured the overall magnitude (PC1) of wavelet intensities across the time-frequency domain and a shift among the range of frequencies (PC2) where wavelet intensities were most prominent. A main effect for group indicated that people with CAI demonstrated smaller (p = 0.009) PC1 scores than people in the CON group across all muscles and tasks. An interaction between group and task indicated that people in the CAI group exhibited smaller (p = 0.041) PC2 scores than people in the CON group during only anticipated cutting. SignificancePeople with CAI exhibited neuromuscular deficits in the time-frequency domain of EMG during dynamic tasks. These deficits appear to reflect a neuromuscular strategy characterized by the recruitment of fewer motor units in ankle muscles regardless of task, and an inability to scale the recruitment of motor units in the frequency domain in response to different task demands. Rehabilitation for people with CAI should consider that this population exhibits differences in neuromuscular control that exist not only in the overall magnitudes, but also in the time-frequency domain, of muscle activation patterns.

How many strides are required for the analysis of electromyographic data in gait?

This study was conducted to obtain information on the number of strides of EMG data needed per subject in a gait study. Ten strides of EMG data were cumulated on eight subjects for each of the soleus, rectus femoris, biceps femoris, vastus medialis and tibialis anterior muscles. The linear envelope of the EMG, normalized in time and amplitude, demonstrated a very high level of stability for a given subject, relative to the variability that was found across subjects. It was concluded that three strides of EMG data per subject provides information as reliable as that obtained from twelve strides.

Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance.

Introduction: Persons with MS (PwMS) have markedly reduced push-off and toe-clearance during gait compared to healthy subjects (HS). These deficits may result from alterations in neuromotor control at the ankle. To optimize rehabilitation interventions for PwMS, a crucial step is to evaluate if and how altered neuromotor control, as represented by muscle synergies, improves with rehabilitation. In this study we investigated changes in ankle motor control and associated biomechanical parameters during gait in PwMS, occurring with increase in speed after gait rehabilitation.Methods: 3D motion and EMG data were collected while 11 PwMS (age 50.3 + 11.1; EDSS 5.2 + 1.2) walked overground at self-selected speed before (T0) and after 20 sessions (T1) of intensive treadmill training. Muscle synergies were extracted using non-negative matrix factorization. Gait parameters were computed according to the LAMB protocol. Pearson's correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in distal module activations representing neuromotor control at the ankle [Forward Propulsion (FPM) and Ground Clearance modules (GCM)], each module's activation timing was integrated over 100% of the gait cycle and the activation percentage index (API) was computed in six phases.Ten age matched HS provided two separate speed-matched normative datasets for T0 and T1. For speed independent comparison for the PwMs Z scores were calculated for all their gait variables.Results: In PwMS velocity increased significantly from T0 to T1 (0.74–0.90 m/s, p < 0.05). The activation profiles (API) of FPM and GCM of PwMS improved in pre-swing (p < 0.05): FPM (Mean [95% CI] [%]: T0: 12.5 [5.7–19.3] vs. T1: 9.0 [2.7–15.3]); GCM (T0: 26.7 [18.2–35.3] vs. T1: 24.5 [18.2–30.7]). This was associated with an increase in toe clearance (80.3 to 103.6 mm, p < 0.05) and a higher ankle power peak in pre-swing (1.53–1.93 W/kg, p < 0.05).Conclusion: Increased gait speed of PwMS after intensive gait training was consistent with improvements in spatio-temporal gait parameters. The most important finding of this study was the re-organization of distal leg modules related to neurophysiological changes induced by rehabilitation. This was associated with an improved ankle performance.

Quantitative Assessment of Traumatic Upper-Limb Peripheral Nerve Injuries Using Surface Electromyography.

BackgroundThere is a great demand for convenient and quantitative assessment of upper-limb traumatic peripheral nerve injuries (PNIs) beyond their clinical routine. This would contribute to improved PNI management and rehabilitation.ObjectiveThe aim of this study was to develop a novel surface EMG examination method for quantitatively evaluating traumatic upper-limb PNIs.MethodsExperiments were conducted to collect surface EMG data from forearm muscles on both sides of seven male subjects during their performance of eight designated hand and wrist motion tasks. All participants were clinically diagnosed as unilateral traumatic upper-limb PNIs on the ulnar nerve, median nerve, or radial nerve. Ten healthy control participants were also enrolled in the study. A novel framework consisting of two modules was also proposed for data analysis. One module was first used to identify whether a PNI occurs on a tested forearm using a machine learning algorithm by extracting and classifying features from surface EMG data. The second module was then used to quantitatively evaluate the degree of injury on three individual nerves on the examined arm.ResultsThe evaluation scores yielded by the proposed method were highly consistent with the clinical assessment decisions for three nerves of all 34 examined arms (7 × 2 + 10 × 2), with a sensitivity of 81.82%, specificity of 98.90%, and significate linear correlation (p < 0.05) in quantitative decision points between the proposed method and the routine clinical approach.ConclusionThis study offers a useful tool for PNI assessment and helps to promote extensive clinical applications of surface EMG.

Diagnosis of Hand Tremor from EMG Sensors

Parkinson’s disease (PD) initially affects on motor activities of the patient. The symptoms of the disease include tremors, muscular rigidity, changes in gait, and complications in speech. In this paper, the experimental procedure for the acquisition of EMG and accelerometer data is explained. From the data, tremor frequency is evaluated. Tremor is an involuntary shaking of the body or the limbs which is considered as an early symptom of Parkinson’s disease. EMG instrument, sensors, selection of muscles in the study, data acquisition procedure, analysis of EMG and accelerometer signal are discussed in this paper. Then the signals were analyzed in the frequency domain to assess tremor frequency in the hand. Since the signals were taken from the underlying muscles of the skin, the results are relatively accurate than indirect methods of hand tremor assessment. Cite as: Mousa M. AL-Mutari, K. Prahlad Rao, Ibrahim M. Mehedi (2020). Diagnosis of Hand Tremor from EMG Sensors. Journal of Technological Science & Engineering (JTSE), 01(01), 30-35. http://doi.org/10.5281/zenodo.3940857

Muscle fatigue evaluation with EMG and Acceleration data: a case study.

The design of effective rehabilitation protocols relies on the ability to accurately assess the physical condition and the rehabilitative needs of the patient. Monitoring muscle fatigue can increase the usability of rehabilitative and restorative devices as it helps avoiding premature tiring and injury of patients whose resistance is already compromised. In this study, we collected EMG and accelerometer data from one healthy subject during a 30-minute walk on treadmill to determine the variations of muscle activation, and gait acceleration patterns, which, however subtle, could be interpreted as early indicators of muscle fatigue. Results show an increasing Tibialis Anterior (TA) and decreasing Soleus (SOL) and Gastrocnemius (GASL, GASM) activation towards the end of the task as compared to the beginning, as well as increasing acceleration peaks during the middle swing phase. By following the approach outlined here we can assess the efficiency and reduction of metabolic cost achieved by an exoskeleton. Furthermore, muscle fatigue may be linked to the efficacy of gait rehabilitation, where decreased muscle fatigue across sessions possibly indicates longer retention of benefits after training and increased walking capacity. This methodology can be used to benchmark novel exoskeletons, monitor fatigue to avoid premature tiring of patients, and optimize rehabilitation therapies.